Familial Risk for Exceptional Longevity

One of the most glaring deficiencies in the current assessment of mortality risk is the lack of information concerning the impact of familial longevity. In this article we update estimates of sibling relative risk of living to extreme ages using data from more than 1700 sibships, and we begin to examine the trend for heritability for different birth-year cohorts. We also build a network model that can be used to compute the increased chance for exceptional longevity of a subject, conditional on his or her family history of longevity. The network includes familial longevity from three generations and can be used to understand the effects of paternal and maternal longevity on an individual's chance to live to an extreme age.     

The evolutionary stability of perfectly competitive behavior

Summary. In a (generalized) symmetric aggregative game, payoffs depend only on individual strategy and an aggregate of all strategies. Players behaving as if they were negligible would optimize taking the aggregate as given. We provide evolutionary and dynamic foundations for such behavior when the game satisfies supermodularity conditions. The results obtained are also useful to characterize evolutionarily stable strategies in a finite population.Received: 29 December 2002, Revised: 27 January 2004, JEL Classification Numbers: C72, D41, D43.An earlier version of this paper was titled The Evolutionary Logic of Feeling Small and was written while the first author was affiliated with the University of Salamanca (Spain). We are indebted to Ken Binmore, Larry Blume, Luis Corchón, Georg Kirchsteiger, Paco Marhuenda, Akihiko Matsui, Diego Moreno, Manfred Nermuth, Klaus Ritzberger, Jörgen Weibull, an anonymous referee, and seminar participants at the universities of Vienna, Carlos III de Madrid, and Salamanca for many helpful comments and suggestions. Obviously, only the authors are responsible for any errors and omissions. We gratefully acknowledge financial support from the Austrian Science Fund (FWF) under Project P15281 as well as from the Austrian Exchange Service (ÖAD) and the Spanish Ministry of Education and Culture under the Spain-Austria Acciones Integradas respective projects HU02-4 and 18/2003.     

An evolutionary analysis of insurance markets with adverse selection

The equilibrium nonexistence problem in Rothschild and Stiglitz's insurance market is reexamined in a dynamic setting. Insurance firms are boundedly rational and offer menus of insurance contracts which are periodically revised: profitable competitors' contracts are imitated and loss-making contracts are withdrawn. Occasionally, a firm experiments by withdrawing or innovating a random set of contracts. We show that Rothschild and Stiglitz's candidate competitive equilibrium contracts constitute the unique long-run market outcome if innovation experiments are restricted to contracts which are sufficiently “similar” to those currently on the market.     

CAPABILITIES AS FUNDAMENTAL ENTITLEMENTS: SEN AND SOCIAL JUSTICE

Amartya Sen has made a major contribution to the theory of social justice, and of gender justice, by arguing that capabilities are the relevant space of comparison when justice-related issues are considered. This article supports Sen's idea, arguing that capabilities supply guidance superior to that of utility and resources (the view's familiar opponents), but also to that of the social contract tradition, and at least some accounts of human rights. But I argue that capabilities can help us to construct a normative conception of social justice, with critical potential for gender issues, only if we specify a definite set of capabilities as the most important ones to protect. Sen's "perspective of freedom" is too vague. Some freedoms limit others; some freedoms are important, some trivial, some good, and some positively bad. Before the approach can offer a valuable normative gender perspective, we must make commitments about substance.     

Manual and Automated Procedures for Compiling a Very Large Sample of Centenarian Pedigrees

A large portion of the baby boomer population will live beyond the age of 90 years, and entitlement programs and various insurance products have thus become interested in longevity risk. Beyond cohort life table predictions, actuaries have little to go on in determining which individuals or portions of populations are at increased risk of living to 90 or 100 or even older. We and others have noted strong familial risk for living beyond the oldest one percentile of survival, and we developed an algorithm that uses information about relatives’ longevity to compute the chance of an individual surviving to extreme old age. An important step of this work is to compile large samples of pedigrees with and without long-lived family members. Here we describe our process of hand curation of centenarian pedigrees and software that we have developed for the automated construction of such pedigrees using internet-based resources that can support the manual process.